Made generate/verify signature importable from views.serve

... and deprecated wagtailimages/utils.py

wagtail/wagtailimages/tests/test_admin_views.py

@@ -12,7 +12,7 @@ from django.utils.http import urlquote
 
 from wagtail.tests.utils import WagtailTestUtils
 from wagtail.wagtailcore.models import Collection, GroupCollectionPermission
-from wagtail.wagtailimages.utils import generate_signature
+from wagtail.wagtailimages.views.serve import generate_signature
 
 from .utils import Image, get_test_image_file
 
@@ -25,8 +25,6 @@ except ImportError:  # < Django 1,8
     urlquote_safechars = '/'
 
 
-
-
 class TestImageIndexView(TestCase, WagtailTestUtils):
     def setUp(self):
         self.login()

wagtail/wagtailimages/tests/tests.py

@@ -17,8 +17,7 @@ from wagtail.wagtailimages.formats import Format, get_image_format, register_ima
 from wagtail.wagtailimages.forms import get_image_form
 from wagtail.wagtailimages.models import Image as WagtailImage
 from wagtail.wagtailimages.rect import Rect, Vector
-from wagtail.wagtailimages.utils import generate_signature, verify_signature
-from wagtail.wagtailimages.views.serve import ServeView
+from wagtail.wagtailimages.views.serve import ServeView, generate_signature, verify_signature
 
 from .utils import Image, get_test_image_file
 

wagtail/wagtailimages/utils.py

@@ -1,7 +1,11 @@
 from __future__ import absolute_import, unicode_literals
 
-from wagtail.wagtailimages.views.serve import ServeView
+import warnings
 
+from wagtail.utils.deprecation import RemovedInWagtail15Warning
+from wagtail.wagtailimages.views.serve import generate_signature, verify_signature  # noqa
 
-generate_signature = ServeView().generate_signature
-verify_signature = ServeView().verify_signature
+warnings.warn(
+    "The 'generate_signature' and 'verify_signature' functions have been moved. "
+    "Please import them from the 'wagtail.wagtailimages.views.serve' module instead.",
+    RemovedInWagtail15Warning)

wagtail/wagtailimages/views/images.py

@@ -17,7 +17,7 @@ from wagtail.wagtailimages.exceptions import InvalidFilterSpecError
 from wagtail.wagtailimages.forms import URLGeneratorForm, get_image_form
 from wagtail.wagtailimages.models import Filter, get_image_model
 from wagtail.wagtailimages.permissions import permission_policy
-from wagtail.wagtailimages.utils import generate_signature
+from wagtail.wagtailimages.views.serve import generate_signature
 from wagtail.wagtailsearch.backends import get_search_backends
 
 permission_checker = PermissionPolicyChecker(permission_policy)

wagtail/wagtailimages/views/serve.py

@@ -75,3 +75,5 @@ class ServeView(View):
 
 
 serve = ServeView.as_view()
+generate_signature = ServeView().generate_signature
+verify_signature = ServeView().verify_signature